vCJD could be transmitted through blood transfusions

A study in sheep shows that BSE can be transmitted between individuals of the same species by whole blood transfusion.

By (medwire@sciencenow.com) | September 15, 2000

LONDON, September 15 (SPIS MedWire). UK scientists have released preliminary data that suggests bovine spongiform encephalopathy (BSE), which is caused by the same agent as variant Creutzfeld–Jakob disease (vCJD), could be passed on by blood transfusions. Reporting their study in the September 16 issue of the Lancet, Fiona Houston and colleagues from the Institute for Animal Health in Edinburgh, UK, say that "blood donated by symptom-free vCJD-infected human beings may represent a risk of spread of vCJD infection." Their conclusion is based on research that involved feeding BSE-infected cattle brain to healthy sheep. Blood was taken from 19 infected sheep before any symptoms developed, then transfused into healthy sheep. Just under two years after the transfusion, one of the sheep began to show signs of BSE; although the study has three years to run, this finding was rushed into print to allay fears of a cover-up at the end of the experiment. "Although this result is only in one animal, it indicates that BSE can be transmitted between individuals of the same species by whole blood transfusion," Dr Houston said. She admitted, however, that it was not known which part of the blood harboured the infectious agent, although all the evidence points to leucocytes, which are routinely filtered out during human transfusions. In an accompanying Commentary, Paul Brown (National Institutes of Health, Bethesda, MD, USA) notes that the study provides "convincing evidence" of transmission, buturges caution in interpreting such a preliminary finding.